I thought I was the only person having this issue, since I couldn't find anything about this. There is definitely an issue with some network adapters. In my case, the Marvell Avastar 350N network controller on my Surface Pro 2. Granted, my SP2 is getting a bit long in the tooth, but I have tried multiple times to upgrade to 16215 using various methods to update the drivers, with no love to be found. I've finally just resorted to moving to the Slow ring for now until it is resolved (hopefully).
Really wanted to be on this build because they added so much great stuff